In this SBIR FastTrack proposal, Micro-Leads will develop HD64?a high-resolution, 64- channel spinal cord stimulation therapy to provide more pain relief with greater specificity for those suffering from chronic neuropathic pain and opioid dependence. Over 25 million in the U.S. suffer from debilitating pain in the trunk and extremities and 55% depend on opioids to ease their suffering. Opioid abuse has claimed the lives of over 200,000 over the past decade and has resulted in devastating reductions in quality of life, in ability to work, and in mental health for the living. Spinal cord stimulation (SCS) has provided pain relief for 60% of those with chronic extremity pain and eliminated opioid use entirely in more than 50%. Despite these advantages, SCS has had a limited success treating isolated pain of the knee, foot, groin, or low-back. The lateral positioned fibers of the spinal cord (ex. the dorsal root entry zone and dorsal horn) represent a more selective neural targeting opportunity yet current, implantable plate-type surgical leads are too rigid and bulky to access these fibers without a significant risk of paralysis or nerve root compression. HD64 provides an ultra-thin and conformal blanket of stimulation contacts across the entire width of the spinal cord. Active-lead technology embeds a tiny electronic chip within the surgical lead and doubles the number of therapy contacts compared with current technology without increasing the number of lead-wires. Collectively, these features improve therapy and simplify surgical workflow. A novel Active-Lead Controller Implantable Pulse Generator (AL-IPG) powers the chip safely, synchronizes with the active-lead electronics, configures the 8 programmable ?therapy groups?, and ensures therapy pulses are delivered to the tissue. HD64 therapy is a highly significant, novel solution for the treatment of patients suffering from chronic pain and opioids. PHASE 1: A cadaveric pilot run followed by a non-significant risk intraoperative study (n=6) will be performed to inform the geometric and electrophysiological design parameters of high-resolution HD64 arrays. The study will evaluate activation of medial and lateral spinal targets as measured by intraoperative neuromonitoring of electromyography. At the end of Phase 1, the clinical feasibility of HD64 surgical leads will be established. PHASE 2: In Phase 2, we have HD64 active leads assembled by a GMP manufacturer. We will develop an external Active Lead Pulse Generator and charger which will be submitted for IDE approval. We will perform an Early Feasibility Study Human Trial using active HD64 and AL-IPG hardware (n=10 subjects, n=23 therapy groups, n=2 waveforms). During Phase 2, we will also perform mechanical and electrical design verification testing and chronic safety studies in large animals to demonstrate functional performance to inform the final device. By the end of Phase 2, we will have completed all necessary tasks to inform the final device design and to enable follow-on implanted longitudinal studies of chronic pain and opioid reduction.